Automatically operated circuit breaker



Sept. 29, 1931. E. C. RANEY 1,s"25,o15

AUTOMATICALLY OPERATED CIRCUIT BREAKER Filed Dec. 9' 1925 2 Sheets-Sheet2 AIIIIIIIIH llllfll! HMI;

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Patented Sept. 29, 1931 ESTEL C. BANEY, OF COLUMBUS, OHIO AUTOMATICALLYOPERATED CIRCUIT BREAKER Application led December My invention relatesto an automatically` operated circuit breaker or switch mechanism of thetype which opens automatically upon over load and recloses automaticallyat the expiration of a time interval.

In the operation of power distributing circuits accidental shortcircuits often occur between wires, due to various causes, such asswinging of wires during storm, falling birds coming in contact withwires, et cetera. In a great many instances, these short circuits are ofa temporary nature and often thely; can be cleared by closing thecircuit brea er or oil switch two or three' times successively. In'othercases these short circuits are of a permanent nature and can only berectified by repairmen.

The purpose of this invention is to provide an efficient means ofoperating the circuit breaker or oil switch so that in the event ofopening, due to overload or short circuit, the circuit breaker willreclose again automatically at the expiration of a short time intervalfor a given number of times, after which its reclosing mechanism will berendered inoperative if the overload or short circuit still exists.

For this purpose, I thermal operated relay, having the contact members.operated by means of an. expansion member containing a volatile liquid,and a suitable resistance element for heating the liquid. This formofIrelay is simple'in construction and positive in action. The timerequired to operate it can -readily be varied by regulating the amountof resistance of the heat element, or the current supplied thereto.

In the drawings, Figure 1 is a diagrammatic representation of one typeof the. above-described mechanism, showing the parts in normal closedposition.

Figure 2 shows the position of parts at a brief time interval afteropening.

Figure 3 shows a similar arrangement except that the operating mechanismis energized from a battery or source of power other than the feedercircuit.

Figure 4 is la sectional view of one form of preferably use a 9, 1925.Serial No. 74,401.

liquid containing structure that may be used as a thermal time limitrelay.

Referring to the drawings, numerals 1 indicate main Contact membersconnecting supply wires 2, 3, and 4 with feed wires 5, 55 6, `and 7,respectively. The contacts 1 are operated by means of coil 8 whichy isenergized from supply wires 3 and 4. I

A control coil 9 effects the initial closing of the circuits for coil 8.A retarding device 10 controls the time required for contact 11 to closeafter being released by the opening of the breaker.

The thermal operated relay having a contact 12 serves to interrupt thecircuit of the 65 operating mechanism of the circuit breaker in case ofa sustained overload or short circuit. This relay comprises a containerthat may be formed in one part or may be formed in two parts as shown at30 and 24. In the 70 latter form, the member 30 is not expansible Whilethe member 24 is expansible and they both contain a highly volatileliquid, being connected by a small tube 3l which has its lower end 32adjacent the bottom of the 75- container portion 30. The containerportion 30 is placed in juxtaposition to the resistance member 23through which current will pass Whenever the circuit breaker is open fora relatively prolonged period of time. The 30 heat of the member 23will, in the event of a relatively prolonged opening of the circuitbreaker, cause volatilization of a portion of the liquid in thecontainer member 30 with the result that the vapor. produced will risea5 to the upper portion 33 inv member 30 through the tube 31 into member24 and thus extend the member 24 to open the contact member 12.

Under normal operation, coil 8 receives 90 energy from wire 3 throughoverload relay contact 13, wire 14, terminal 15, maintaining contact 16,terminal 17 coil 8, wire 18, contact 12, wire 19, overload contact 29 towire 4. In the event of overload on wire 2 or 4, 95 either or both ofoverload contacts 13 and 20 will be momentaril opened, resulting inde-energizing coil 8, wlth the resultant opening of main contacts 1.With the contacts 1 1n open position, the circuit of coil 8 is also 100the expiration of a short time interval, as determinedby the adjustmentof 10,'the circuit of coil 9 is completed. This permits the contact 21to close the circuit of coil 8 around contacts 15 and 17. This permitscoil 8 to ybe again energized and, in closing the main contacts 1, thecontact 16 is rst brought into contact with points 15 and 17 after whichcontact 11 is opened and the parts assume the normal position vshown inlgure 1.

At the instant of opening of main cong tacts 1, an auxiliary contact 22,Figure 2,

closes and com letes the circuit of heating element 23. A er a shorttime interval, the breaker will again close but, if the overload orshort circuit remains, the breaker will again open instantly and theheat element will again be connected so that the cumulative effect oftheheat generated in 23 will result in vaporizing a portion of the liquidin the container member 30, The vapor will rise to the upper portion 33of the container 30 and displace a portion of the liquid which will beforced up through the tube 31 and will extend the member 24. Theextending of the member 24 will open the contact 12 in a deinite timeafter the overload or short circuit occurs. Thus if the main breakerremains open for a long time interval, or there isa large aggregate ofsuccessive open periods, the main breaker will be'rendered permanentlyinoperative to reclose. The length of the interval or the number oftimes the breaker will reclose before heat element 23 raises thepressure in expansion member 24 suciently to operate the contact 12,depends upon the relative timing adjustment of retarding device 10 andheat element 23. This relation may be made any desired value. Contact.12is preferably so arranged as to remain open permanently after openinguntil reset by an attendant.

From the foregoing, it will be evident that I have provided vaneffective means of controlling the operation of a circuit breaker or oilswitch, so that momentary overload will not seriously interrupt serviceon a distributing system, and yet the system will be eectively protectedinthe event of a sustained overload or short circuit.

Having thus described my invention, what I claim is: y

1. In a three wire circuit, a plurality of main breakers, a mainbreakerlocated in each of the said wires, means for automatically reclosing thesaid breakers, means for rendering said reclosing means inoperative andcomprising a switch and a resistance element, a thermostat elementlocated in operative relation to the resistance element, the resistanceelement energized when the main breakers are open to heat'the thermostatelement to cause the thermostat element after a certain time to operatethe switch to render the said reclosing means permanently inoperative,if the main breakers remain open for a too long time interval eithercontinuously or an aggregate of successive open periods during the saidtime interval.

2. In combination with an automatically reclosing'circuit breaker of ameans automatically operated to render the reclosing means permanentlyinoperative if the circuit breaker remains open .for a too long timeinterval either continuously or an aggregate of successive open periodsduring said time interval, said means having an element expansible byheating.

` 3. The combination with an automatically reclosing circuit breaker ofa means autr matically operative to render the reclosing meanspermanently inoperative, if the circuit breaker remains open for a toolong a time interval, either continuously or an aggregate of successiveopen periods during said time interval, said means having a switch, anexpansible container containing a volatile liquid vaporizable by heatingand means for heating the liquid, the switch being operated by theexpansibleforce of said i uid. i

qd. In a circuit, a main'breaker located in the said circuit, means forautomatically reclosing the said breaker, means for rendering saidreclosing means inoperative comprisinga switch, a resistance element anda thermostat element, the thermostat element located in operativerelation to the resistance element, the resistance element energized vsubstantially equal to the said time interval;

In testimony whereof T have hereunto signed my name to thisspecification.

ESTEL C. RANEY.

